My ex-wife claims that this is the reason she started sleeping with someone else. I don't really buy it. I guess I could have if it had been a one time fling...but after we split, she continued the torrid affair (that was a small town scandal, btw) even shacking up with the guy...then dropping him for someone else. I told her "Gee thanks, next time don't try so hard to do me any favors". It's part of the reason for our bitter animosity to this day. Maybe she really did it because she's a swivel hipped whore instead....it seems more likely.
In HER case, it seems that the idea of "setting me free" was simply an excuse to justify her conduct. As some others mentioned, I have also seen cases where one waits for the other to slip up and that's no way to live.
Ern